The present invention relates to an airbag apparatus, and more particularly, to an airbag apparatus which is preferably applicable to a passenger side airbag apparatus installed in the instrument panel of a vehicle. More specifically, the present invention relates to an airbag apparatus having a casing with a thick plate portion. Further, the present invention relates to a casing used in the airbag apparatus.
There is known an airbag apparatus, wherein a thick plate is attached to a casing, and a lid is locked to hook members of the thick plate, as a passenger-side airbag apparatus.
FIG. 9 is a sectional view showing a conventional airbag apparatus. The airbag apparatus 1 is composed of an inflator 2 for generating a gas in a collision of a vehicle and the like, a casing 3 for accommodating the inflator 2, an airbag 5 accommodated in the casing 3 in a folded state, and a lid 6 for closing an uncovered opening at the upper portion of the casing 3. The airbag apparatus 1 is attached to an instrument panel 9. Thick plates 10 and 11 are secured to upper outer surfaces of the casing 3 by spot welding. The thick plates 10 and 11 extend along upper edges of the casing 3, and a plurality of pawl-shaped hook members 12 is disposed integrally with the thick plates 10 and 11 in the extending direction thereof at appropriate intervals. The legs 7 of the lid 6 have openings 13 corresponding to the hook members 12 to engage therewith. A thin wall section 8 is formed on the inner surface of the lid 6.
When the lid 6 is mounted on the casing 3 to assemble the airbag apparatus 1, the lid 6 is pushed so as to close the uncovered opening of the upper surface of the casing 3. With this operation, the legs 7 of the lid 6 pass over the hook members 12 while being elastically deformed externally, and return to their original shapes when the hook members 12 are in conformity with the openings 13, so that the hook members 12 are caught by the inner edges of the openings 13.
In the airbag apparatus arranged as described above, when the inflator 2 is actuated, the airbag 5 is deployed, and the lid 6 is broken and opened along the thin wall section 8, whereby the airbag 5 is unfolded into a compartment.
The strength required for the casing 3 can be reduced by attaching the thick plates 10 and 11 to the casing 3, and locking the lid 6 to the hook members 12 of the thick plates 10 and 11, as shown in FIG. 9. As a result, it is possible to reduce the wall thickness of the casing 3 and to decrease the weight of the casing 3.
Incidentally, an instrument panel of a vehicle must have a energy absorbing function for absorbing energy generated when a passenger hits thereto in such a manner that the instrument panel is gradually deformed. The casing and the lid of the passenger side airbag apparatus which is installed in the instrument panel also must have the energy absorbing function.
Japanese Utility Model Publication (KOKAI) No. 6-22116 discloses that a bent section with an approximately V-shape in a cross section is disposed on a side surface of a casing, and the casing is deformed at the bent section when a passenger hits the airbag apparatus.
An object of the present invention is to provide an airbag apparatus having an energy absorbing function which is more enhanced than that disclosed in Japanese Utility Model Publication No. 6-22116 and a casing of the airbag apparatus.
In a first aspect of the invention, an airbag apparatus comprises a casing, a front surface of which is arranged as an uncovered opening, an airbag accommodated in and coupled with the casing, a gas generator for supplying a gas into the airbag and deploying the airbag, a thick plate secured to a side surface of the casing, and a lid for covering the uncovered opening. In the airbag apparatus, at least a rear or lower side portion of the thick plate is secured to a side surface or portion of the casing, and the rear side portion of the thick plate and a portion of the side surface of the casing secured to the rear side portion of the thick plate project outwardly.
In a second aspect of the present invention, an airbag apparatus comprises a casing, a front surface of which is arranged as an uncovered opening, an airbag accommodated in and coupled with the casing, a gas generator for supplying a gas into the airbag and deploying the airbag, and a lid for covering the uncovered opening. In the airbag apparatus, a front or upper portion, which is near the uncovered opening, of a side surface section of the casing is composed of a thick plate, the thickness being greater than a rear or lower portion of the side surface section, and the rear portion is composed of a thin plate. A rear or lower side of the thick plate and a portion, which is continuous to the rear side, of the thin plate project outwardly of the casing.
In a third aspect of the invention, a casing of an airbag apparatus for accommodating an airbag includes an uncovered opening at a front surface or upper portion of the casing, and a thick plate is disposed on a side surface of the casing along an edge of the uncovered opening. In the casing, at least a rear or lower side portion of the thick plate is secured to a side surface or portion of the casing, and the rear side portion of the thick plate and a portion of the side surface of the casing secured to the rear side portion of the thick plate project outwardly.
In a fourth aspect of the invention, a casing of an airbag apparatus for accommodating an airbag includes an uncovered opening at a front surface or upper portion of the casing. In the casing, the upper portion, which is near the uncovered opening, of a side surface section of the casing is composed of a thick plate whose thickness is greater than a rear or lower portion of the side surface section, and the rear portion is composed of a thin plate. The rear side portion of the thick plate and a portion continuous to the rear side portion of the thin plate project outwardly of the casing.
In the casing and the airbag apparatus using the casing of the present invention, when a passenger hits the casing or the airbag apparatus, the rear or lower side portion of the thick plate is deformed and project outwardly. At the time, the portion of the casing continuous to the thick plate is deformed so as to be drawn externally, whereby an energy is absorbed.
It is preferable that the rear side portion of the thick plate is bent obliquely relative to a portion located above the rear side portion.
In the present invention, the casing is composed of metal or a synthetic resin.